Lec 29 Motor System Clinical Correlations

Question 1

Do you get spasticity in UMN or LMN lesion?

Answer 1

UMN

Question 2

What is typicall distribution of weakness in upper motor neuron lesion?

Answer 2

in upper extremities: flexors stronger than extensors

in lower extremities: extensors are stronger than flexors

look at shoes: adductors stronger than abductors –> outside may be more worn

Question 3

Do you see babinski [big doe upgoing] in UMN or LMN lesion?

Answer 3

in UMN lesions

Question 4

What are some examples of UMN lesions?

Answer 4

cerebrovascular accident [stroke], intracranial tumor, cervical spine injury

Question 5

What are some examples of LMN lesions?

Answer 5

motor neuron disease, peripheral nerve neuropathy, polio, spinal cord injury resulting in nerve root compression

Question 6

What is normal reflex on the scale?

Answer 6

2+ is normal

Question 7

What is normal muscle strength on the scale?

Answer 7

5

3 = against gravity

Question 8

What is hemiplegic gait?

Answer 8

• arm in flexion with weakness of extensors of fingers/wrist
• hand and fingers tightly clenched
• outward swing of leg
• reduced arm swing

Question 9

what is spastic gait?

Answer 9

• both legs stick, have toe walking
• walking slow and stiff
• bilateral
• hyperreflexia

Question 10

what is frontal [magnetic] gait?

Answer 10

• difficulty getting out of chair and finding center of gravity
• small steps as if feet stuck to ground

Question 11

What disease is frontal [magnetic] gait associated with?

Answer 11

seen in normal pressure hydrocephalus –> on exam usually cognitive impairment

Question 12

What is amyotrophic lateral sclerosis?

Answer 12

combined anterior horn + pyramidal tract disease = UMN and LMN
- no sensory, cognitive, or oculomotor deficits

characterized by: rapid progressive weakness, muscle atrophy and fasciculations, muscle spasticity, difficulty speaking, difficulty swallowing, difficulty breathing

Question 13

Causes of ALS?

Answer 13

can be due to defect in superoxide dismutase 1

Question 14

What are 2 viruses that can affect anterior horn?

Answer 14

• polio

- west nile

Question 15

What is treatment for ALS?

Answer 15

riluzole [prolongs survival 2-3 mo]

prognosis = 3-5 years

Question 16

What are other disease that might present like ALS? how do you determine ALS?

Answer 16

• determine ALS by demonstrating disease above foramen magnum [ex. dysarthria, swallowing disorder, jaw jerk]

otherwise could be: tumor of brainstem or cervical spondylosis

Question 17

What is primary lateral sclerosis?

Answer 17

• UMN, no LMN involvement
• lesion of motor cortex
• slowly progressive spastic quadriparesis

Question 18

what is progressive spinal muscular atrophy?

Answer 18

• LMN, no UMN involvement

- weakness, wasting, fasciculations with variable age onset

Question 19

What is cervical spondylosis?

Answer 19

can be UMN and LMN involvement

but no involvement above foramen magnum

Question 20

What presentation in a lesion of motor cortex?

Answer 20

• UMN disease

ex. primary lateral sclerosis

Question 21

what presentation in a lesion of internal capsule?

Answer 21

• contralateral motor or sensory deficit

Question 22

What presentation in a lesion of brainstem?

Answer 22

• ipsilateral cranial nerve deficits + contralateral motor deficits
• jaw jerk reflex impaired

Question 23

what presentation in an anterior horn spinal cord injury?

Answer 23

• LMN disease = ipsilateral weakness, atrophy, fasciculations, hyporeflexia
• absence of cognitive or sensory changes

ex. spinal muscular atrophy, polio, west nile

Question 24

what presentation in peripheral neuropathy?

Answer 24

• distal weakness [longest nerves first]
• steppage gate [LMN leg weakness]
• foot drop
• weakness/hyporeflexia

Question 25

What is guillain barre?

Answer 25

type of peripheral neuropathy
get ascending paralysis
associated with campylobacter infection

Question 26

What presentation in NMJ disorder?

Answer 26

• fluctuating wekness, fatigable muscles

dysarthria, dysphagia, diplopia, ptosis

Question 27

What is myasthenia gravia?

Answer 27

type of NMJ disorder

• autoantibodies against ACh receptor
• muscle weakness, ptosis, gets worse with use

Question 28

What presentation in myotonia?

Answer 28

disorder of muscle membrane

• slow relaxation of muscle after voluntary contraction
• improves when muscle warmed

Question 29

what presentation in myopathy?

Answer 29

• proximal weakness
• normal sensation, normal sphincter, preservation deep tendon reflex
• gowers sign

Question 30

what is gower’s sign?

Answer 30

arms/hands used to get body out of seated position

sign of muscle myopathy

Question 31

What does steppage gate suggest?

Answer 31

LMN leg weakness

Question 32

What is acute inflammatory demyelinating polyradiculopathy?

Answer 32

• most common variatn of guillain barre
• autoimmune disorder destroys schwann cells
• get inflammation and demyelination of peripheral nerves and motor fibers

Question 33

What are sigsn of acute inflammatory demyelinating polyradiculopathy?

Answer 33

• symmetric ascending muscle weakness/paralysis beginning in lower extremities
• facial paralysis in 1/2 pts
• high CSF protein
• papilledema

Question 34

How do you treat myasthenia gravis?

Answer 34

ACHesterase inhibitors

Question 35

What is botulism?

Answer 35

• toxin produced by clostridium botulinum prevents ACh release
• paralysis of face, spreads to limbs, ptosis

in kids = floppy baby

Question 36

What is tick paralysis?

Answer 36

due to neruotoxin in tick’s salivary gland

• weakness in both legs –> ascending paralysis
• looks like guillan barre

Question 37

What is ciguatera toxin?

Answer 37

• get ir from ingesting certain fish

- after ingestion –> pts get N/V, weakness, muscular cramps, metallic taste, paralysis, coma, resp failure